Compositions able to indicate when they become inefficient in use

ABSTRACT

The invention concerns a composition aimed to indicate by color change when consumer articles, particularly volatile dispensers, containing or associated with said composition have become inefficient in use.  
     The composition is constituted by a volatile liquid phase, a non-volatile polar phase and a useful amount of a dye originally dissolved essentially in the volatile liquid phase, said dye being able to adopt a different color according to the nature of the phase in which it is dissolved or deposited. Optionally, the composition can also contain an effective amount of an acidic compound.  
     The invention also concerns the use of said composition in a consumer article, in particular a device aimed to diffuse a volatile or partially volatile liquid, more specifically an air freshener.

FIELD OF THE INVENTION

[0001] The invention concerns a composition designed to indicate bycolor change when consumer articles, particularly volatile materialdispensers, containing or associated with said composition, have becomeinefficient in use.

[0002] The composition is constituted by a volatile liquid phase, anon-volatile polar phase and a useful amount of a dye originallydissolved essentially in the volatile liquid phase, said dye being ableto adopt a different color according to the nature of the phase in whichit is dissolved or deposited. Optionally, the composition can alsocontain an effective amount of an acidic compound.

[0003] The invention also concerns the use of said composition in aconsumer article, in particular a device intended to diffuse a volatileor partially volatile liquid, more specifically an air freshener.

BACKGROUND

[0004] The use of compositions able to indicate, by changing theircolor, the loss of efficiency of a consumer article with which thecompositions are associated, is quite wide. The usefulness of suchcompositions is quite apparent, as they allow the visual assessment ofthe right moment at which the consumer article needs to be renewed.

[0005] The known compositions are used in consumer articles such as airfresheners (e.g. see S.C. Johnson, EP 0309173), packaging films (e.g.see University of Akron, U.S. Pat. No. 5,501,945) or coating films (e.g.see Nippon Photograph Printing, JP 03199964).

[0006] In general, changes in a consumer article during its use orstorage, induce the compositions to respond, and therefore to changecolor, indicating the loss of efficiency. The most commonly occurringvariations include pH, redox potential, solvent, pressure or lightirradiation changes.

[0007] European patent EP 309173 discloses the use of a homogeneousindicator composition that includes a volatilizable non-aqueous solvent,a soluble polar indicator dye and a soluble proton donating compound.During the evaporation of the volatilizable non-aqueous solvent, theconcentration of the proton donating compound progressively increases,thus inducing a gradual pH change, the latter producing a gradual colorchange indicating the lost of efficiency. A limitation of such acompostion comes from the fact that the preferred proton donors areliquid and therefore must be less volatile than the solvent in order toensure the functioning of the composition. A further serious drawback ofsuch a composition comes from the fact that the color change, andtherefore the information provided to the consumer concerning theefficiency of the article, occurs only gradually and is spread outthrough the useful life of the article. This gradual change makes itdifficult to asses when the article has effectively become inefficientin use.

[0008] The Japanese document JP 03199964 discloses a printable coatingfilm for discoloration in the course of time, formed by an inkcontaining a powder of (hydro)oxides, a dye, a solvent that has at leastone oxygen atom in its formula and a resin for the binder as essentialcomponents. In said film, the evaporation of the solvent induces thecolor changes.

[0009] In order to achieve a good matching between the rate ofevaporation of the solvent and the effective life of the associatedarticle, the realization of an efficient film is complex and requires avery careful dosing of the quantity of solvent and of the thickness ofthe film. Furthermore, as above, the main weakness consists in the factthat the color change is a gradual one, as clearly stated by theauthors.

[0010] Despite prior known compositions aimed at indicating whenconsumer articles have become inefficient in use, there is still a needfor compositions which are of simple preparation and able to provide anunambiguous indication of the consumer article status through a clearand unambiguous color change.

DETAILED DESCRIPTION OF THE INVENTION

[0011] The object of the present invention is a composition of simplepreparation and to provide a clear and unambiguous indication of theloss of efficiency of consumer articles containing or associated withsaid composition. As consumer articles, volatile material dispensers areparticularly intended.

[0012] The composition of the invention is composed of a volatile liquidphase, a non-volatile polar phase and a useful amount of a dyeoriginally dissolved essentially in the volatile phase, said dye beingable to adopt a variable color as a function of the nature of the phasein which it is dissolved or deposited. Preferably, the dye, whendissolved in the volatile liquid phase, is colorless or has at least acolor clearly distinct from the color that it assumes when deposited onthe polar phase.

[0013] Optionally, the composition can also contain an effective amountoaf an acidic compound, in order to fine tune the moment at which thecolor change occurs.

[0014] As described above, the composition contains a volatile liquidphase. Said volatile liquid phase will be preferably composedessentially of a volatile material that is intended to be dispersed intothe surrounding air by the consumer article with which the compositionof the invention is associated. The volatile liquid will preferably be anon-aqueous liquid.

[0015] As the volatile liquid phase, there can be used for exampleperfumes, in which case the consumer product will be of the airfreshener type. Other suitable volatile liquid phases can be adeodorizing or sanitizing agent or insect repellent, or any othervolatile material capable of imparting perceptible and desirablebenefits to the quality of the air into which it is diffused.

[0016] As the perfume or perfuming ingredients there can be used anyingredient or mixture of ingredients currently used in perfumery. Thelatter can be made of discreet chemicals; more often, however, it willbe a more or less complex mixture of volatile ingredients of natural orsynthetic origin. The nature of these ingredients can be found inspecialized books of perfumery, e.g. in S. Arctander (Perfume and FlavorChemicals, Montclair N.J., USA 1969) or similar textbooks of reference,and a more detailed description thereof is not warranted here.

[0017] Although special mention has been made hereinabove of theperfuming effect that can be exerted by the compositions of theinvention, the same principles apply to the manufacture of analogouscompositions for the diffusion of deodorizing or sanitizing vapors, theperfume base being replaced by a deodorizing composition, a bactericide,an insecticide, an insect repellent or an insect attractant. By the term“sanitizing vapors”, we refer here not only to the vapors of thosesubstances which can enhance the degree of acceptance of the airsurrounding the observer, but also to those substances which can exertan attractant or repellent effect toward certain species of insects, forinstance toward houseflies or mosquitoes, or else, which can havebactericide or bacteriostatic activity. It goes without saying thatmixtures of such agents can also be used.

[0018] As previously mentioned, the polar phase is a material that mustallow the dye, when initially deposited on it, to assume a differentcolor from the color said dye assumes when dissolved in the volatileliquid phase.

[0019] The preferred polar phase is a solid material that is non-solublein the volatile liquid phase, therefore the compositions of theinvention are heterogeneous or biphasic. Said solid material can beselected from the group consisting of the metal oxides and hydroxides ofthe metals in group III and IV of the periodic table. Preferredmaterials for the polar phase are silica gel, alumina and Florisil®(MgSiO₄; origin: Supelco). More preferably the polar phase will bealumina or silica gel.

[0020] The dyes are another component of the composition. As mentionedabove, a dye useful for the composition according to the invention mustbe able to adopt a different color according to the polarity of thephase in which it is dissolved or deposited. Preferably the dye, whendissolved in the volatile liquid phase, is colorless or has a colorclearly distinct from the color that said dye assumes when deposited onthe polar phase.

[0021] Suitable dyes are such that their affinity for the volatileliquid phase is higher than for the polar phase; e.g. the dye will bepreferably dissolved in the volatile liquid phase rather than depositedon the polar phase. The relative affinity of the dye for the two phaseswill determine the fragrance depletion point at which the color changewill appear. The higher the affinity of the dye for the volatile liquidphase, compared to the affinity for the polar phase, the higher will bethe depletion of fragrance when the color change appears.

[0022] By the expression “depletion of fragrance” we mean the percentageof volatile liquid phase which has been released into the airsurrounding the consumer article containing the composition of theinvention.

[0023] As the dye, any current such substance may be employed, providedthat it satisfies the criteria cited herein above. Suitable dyes are, asnon-limiting examples, those of the following families: diarylphthalides and their indol derivatives, diaryl sulphophthaleins, andfluorans.

[0024] Preferred dyes areN-[9-(2-carboxyphenyl)-6-(diethylamino)-3H-xanthen-3-ylidene]-N-ethylethaminefree base commonly known as Rhodamine B base,3,3-bis(1-octyl-2-methylindol-3-yl) phthalide, also known asPergascript® Red I-6B (origin CIBA SC Switzerland),3,3-bis(1-ethyl-2-methylindol-3-yl) phthalide,3,3-bis(1-butyl-2methylindol-3-yl) phthalide,3,3-bis(1-pentyl-2-methylindol-3-yl) phthalide,3,3-bis(4-dimethylaminophenyl)-6-dimethyl amino phthalide, commonlyreferred to as crystal violet lactone, 2′-(bisphenylmethyl)amino-6-(diethylamino)spiro-(isobenzofuran-1(3H),9′-(9H) xanthen)-3-onealso known as malachite green lactone, 3-(4-diethylamino)phenyl-3-(di(4-octyl) phenylamino) t-(3H)-isobenzofuranone and2-anilino-3-methyl-6-diethyl-amino fluoran.

[0025] A fourth component of the composition according to the inventionis an acidic compound. However as already mentioned, the addition to thecomposition of said acidic compound is optional.

[0026] This optional fourth constituent can be a liquid or solidcompound, but it shall in any case be less volatile than the volatileliquid phase. The acid serves as proton donor and causes the dye tobecome protonated and to take the form of the colored open-ring acidrather than the colorless lactone.

[0027] Said acidic compound can be selected from the group constitutedby the chemicals containing at least a proton donating group such as acarboxylic acid or a hydroxyl group. Preferred acidic materials arelauric, stearic, myristic, palmitic acid or diphenol-dimethyl-methane.

[0028] The above-identified constituents of the composition which is theobject of the invention can be admixed in various ratios depending onthe nature of the different constituents.

[0029] One can cite, as non-limiting examples and for all types ofconsumer articles associated with said composition, compositionswherein: a) the dye is present in an amount comprised between 0.007% and2%; b) the polar phase is present in an amount comprised between 0.5%and 12%; c) the acidic compound is present in an amount comprisedbetween 0% and 20%; and d) the volatile liquid phase constitutes thebalance of the composition, percentage being referred to the weight ofthe composition.

[0030] Preferably compositions wherein: a) the dye is present in anamount comprised between 0.01% and 0.5%; b) the polar phase is presentin an amount comprised between 1% and 10%; c) the acidic compound ispresent in an amount comprised between 0% and 5% and d) the volatile andliquid phase constitutes the balance of the composition, percentagebeing referred to the weight of the composition.

[0031] Naturally, it is clear to a person skilled in the art that thevarious components can be admixed in any quantity required to achievethe color change at the desired fragrance depletion point of thearticle.

[0032] As anticipated above, the composition of the invention can becontained in a consumer article, whereby as a consumer article it isintended here more specifically a volatile material dispenser.

[0033] Such a volatile material dispenser can be, depending on thenature of the liquid phase used in the preparation of the composition, aperfuming or sanitizing device such as an air freshener, particularly ofthe membrane-type air freshener, a diaper pail freshener, a carfreshener, a closet freshener, a cat litter box freshener, a shoefreshener or a garbage pail freshener, an insecticide device or aninsect repellent.

[0034] In fact, a container and an adequate composition of the inventionwill compose said consumer article. The composition will be inside thecontainer and at least a portion of the container surface must be madeof a material permeable to the vapors of the volatile liquid phase. Thecontainer can be made of any material usable for this kind of consumerarticle. Naturally said material must be chemically inert toward thecomposition of the invention.

[0035] During storage, the container in which the composition isenclosed is sealed, in order not to allow diffusion of the volatileliquid phase into the surroundings. The consumer will then activate theconsumer article simply by removing the seal, after which the volatileliquid phase will start to diffuse in the surrounding air. Once thevolatile liquid phase has evaporated to such an extent that its desiredaction (e.g. perfuming or insect repellent) starts to fade or has fadedto a certain extent, the composition of the invention will change itscolor, and not before. This technical effect will provide the consumerwith a clear and unambiguous information concerning the efficiency inuse of the article.

[0036] Preferred consumer article is an air freshener operating at roomtemperature or in a small oven, such as a “plug-in” air freshener.

[0037] The invention will now be described in further detail by way ofthe following examples.

EXAMPLES 1 Tuning of the Depletion Point of a Composition According tothe Invention as a Function of Dye Concentration

[0038] An air freshener composition has been prepared by mixing thefollowing ingredients in the indicated amounts: Ingredients Parts byweight Fragrance 96 Amorphous fumed silica gel ¹⁾  4 Lauric acidaccording to table 1 Pergascript Red I-6B ® ²⁾ according to table 1

[0039] Then, 0.25 g of the composition were placed on a 7 cm×7 cm cutpiece of aluminum foil. The initial weight of the solution was measured.The solution on aluminum foil was placed in a 55° C. incubator toincrease the depletion rate of the fragrance. The sample was observedfor any color change every 30 minutes. Once the color change wasobserved, the sample was then weighed, and the percentage of fragrancedepletion calculated. TABLE 1 Influence of the dye/acid concentration onthe depletion point of a composition at the moment of the color changeof the composition: Parts of acid Parts of dye Depletion point* 0.0450.005 Not observed 0.068 0.0075 100  0.09 0.01 84 0.27 0.03 78 0.45 0.0575 0.9 0.1 70 1.35 0.15 66 1.8 0.2 63 2.7 0.3 55 3.6 0.4 49

EXAMPLE 2 Examples of compositions for a Plug-in Air FreshenerComposition (A)

[0040] An air freshener composition was prepared by mixing the followingingredients in the indicated amounts: Ingredients Parts by weightFragrance¹⁾ 9600  Amorphous fumed silica gel¹⁾ 400 Pergascript RedI-6B ®¹⁾  5

Composition (B)

[0041] An air freshener composition was prepared by mixing the followingingredients in the indicated quantities: Ingredients Parts by weighFragrance¹⁾ 960 Amorphous fumed silica gel¹⁾ 40 Lauric acid 3.6Pergascript Red I-6B ®¹⁾ 0.4

General Description of the Device

[0042] 5.1 grams of one of the composition as described herein above wasplaced in a cartridge, one side of said cartridge being composed ofBarex® resin (origin: BP Chemicals) used as a reservoir for thefragranced composition, and the other side being a transparentsemi-permeable membrane of about 150-180 microns thickness and made ofan ethylene ethyl acrylate copolymer, said membrane being used for thediffusion of the fragrance. The cartridge was then placed in an electricheating unit (plug-in type air freshener) to allow diffusion of thefragrance. The unit was plugged in a 120-volt outlet, heating thecartridge to 37° C.

[0043] Note that the cartridge does not necessarily need heat to diffusethe fragrance. Using a more permeable membrane can regulate amount ofheat required. It is possible to use a membrane that is permeable enoughto allow diffusion of the fragrance at room temperature.

[0044] Observations were made over a 45-day time period. Over thisperiod of time, color change and diffusion of fragrance were recorded.

Results for Composition (A)

[0045] As shown in the following table, such a composition is able todisplay a clear change of color after 29 days, or at 67% depletion ofthe fragrance, to indicate when the air freshener starts to becomeinefficient in use. Time (days) Depletion* Observations  0-20  0 to 50no color change 21-28 51 to 66 a very slight pink hue starts to develop29 67 a distinct magenta color is evident 30-45 67 to 85 color becamedarker and change more obvious

Results for Composition (B)

[0046] As shown in the following table, such a composition is able todisplay a clear change of color after 30 days, or at 68% depletion ofthe fragrance, to indicate when the air freshener started to becomeinefficient in use. Time (days) Depletion* Observations  0-22  0 to 52no color change 23-29 53 to 67 a very slight pink hue starts to develop30 68 a distinct magenta color is evident 31-45 69 to 84 color becamedark and change more obvious**

1. A composition intended to indicate by color change when a consumerarticle containing or associated with said composition has becomeineffective in use, said composition being composed of: a) a volatileliquid phase, b) a non-volatile polar phase, c) a useful amount of a dyeoriginally dissolved essentially in the volatile phase, said dye beingable to adopt a variable color as a function of the nature of the phasein which it is dissolved or deposited, d) optionally, a useful amount ofan acidic compound.
 2. A composition according to claim 1, wherein saidpolar phase is essentially composed of a solid material selected fromthe group consisting of the oxides and hydroxides of the metals in groupIII and IV of the periodic table.
 3. A composition according to claim 2,wherein said polar phase is essentially composed of silica gel,silicate, or alumina.
 4. A composition according to claim 1, whereinsaid dye is selected from the group consisting of diaryl phthalides andtheir indole derivatives, diaryl sulphophthaleins and fluorans.
 5. Acomposition according to claim 4, wherein said dye is selected from thegroup consisting ofN-[9-(2-carboxyphenyl)-6-(diethylamino)-3H-xanthen-3-ylidene]-N-ethylethaminefree base, 3,3-bis(1-octyl-2-methylindol-3-yl) phthalide,3,3-bis(1-ethyl-2-methylindol-3-yl) phthalide,3,3-bis(1-butyl-2-methylindol-3-yl) phthalide,3,3-bis(1-pentyl-2methylindol-3-yl) phthalide,3,3-bis(4-dimethylamino-phenyl)-6-dimethyl amino phthalide,2′-(bisphenylmethyl) amino-6-(diethylamino)spiro-(isobenzofuran-1(3H),9′-(9H) xanthen)-3-one, 3-(4-diethylamino) phenyl-3-(di(4-octyl)phenylamino) t-(3H)-isobenzofuranone and2-anilino-3-methyl-6-diethyl-amino fluoran.
 6. A composition accordingto claim 1, wherein a) the dye is present in an amount comprised between0.007% and 2%; b) the polar phase is present in an amount comprisedbetween 0.5% and 12%; c) the acidic compound is present in an amountcomprised between 0% and 20%; and d) the volatile liquid phaseconstitutes the balance of the composition, percentage being referred tothe weight of the composition.
 7. A composition according to claim 6,wherein a) the dye is present in an amount comprised between 0.01% and0.5%; b) the polar phase is present in an amount comprised between 1%and 10%; c) the acidic compound is present in an amount comprisedbetween 0% and 5%; and d) the volatile liquid phase constitutes thebalance of the composition, percentage being referred to the weight ofthe composition.
 8. A composition according to claim 1, wherein saidvolatile liquid phase is a perfume, a deodorizing or sanitizing agent oran insect repellent, or any other volatile material capable of impartingperceptible and desirable benefits to the quality of the air into whichit is diffused.
 9. A composition according to claim 8, wherein saidvolatile liquid phase is a perfume
 10. A consumer article in the form ofa volatile material dispenser containing a composition according toclaim
 1. 11. A consumer article according to claim 10, wherein thevolatile material dispenser is a perfume dispenser.
 12. A perfumedispenser according to claim 11, in the form of an air freshener, aplug-in air freshener, a diaper pail freshener, a car freshener, acloset freshener, a cat litter box freshener, a shoes freshener or agarbage pail freshener.